The 'biggest' game people can create is 40, which unlocks at level 53.
Which settings do you call interesting?
What do you mean by an 'interesting game'?
You should become at least level 47 if you want to include custom scenarios. Custom scenarios are commonly associated with diplomacy game. See https://www.warlight.net/wiki/Custom_scenarios
for information about custom scenarios.
To avoid leveling up to unlock settings, you can buy or get someone to buy you a membership: https://www.warlight.net/membership
. If you're not interested in buying a membership, win games and earn achievements.
I would create the game but I'm currently on vacation...